Hello All, I'm a classical musician with some technical audio experience,
but not a real "engineer".

I'm recording in a beautiful sounding recital hall of about 200 seats. The
hall already had a pair of Neumann KM140s hanging from the ceiling. I'm
recording solo piano (Steinway grand), solo instruments, duets, trios,
quartets and so on. ABout the largest thing I get is a baroque string
ensemble (about 25-30 people) plus harpsichord.

THe problem is, I feel like the sound is a little cold and sterile. Part of
this is I'm not getting much ambient signal (and this is a great sounding
room, so I really feel it's an important part of the experience). The
ceiling is HIGH, and we can't even get to the receptacles without building
scaffolding (which has never happened in the 15 years this building has been
around). The mics hang in an XY pair about 15 feet above the front center
stage, maybe about a foot back from the very front edge of the stage. The
cable lengths, and fixed position in the receptacles prevents my moving them
too much, but I have been able to pull them back so now they hang about 2
feet past the edge of the stage (into the audience) and are now maybe a foot
higher (if that - it's just whatever the angle difference caused).

That's added a little ambience, but of course it's also lessened the low
frequency response a bit.

I've also pulled another pair of the same mics, tried an ORTF like
configuration (as best I could with the mount I have) and put them in the
third row, up on an Atlas stand - about 8 feet in the air - I was figuring
the greater horizontal distance from the sound source would make up for the
lower height than my hanging mics. This is the best stereo spread and warmth
(ambience) I've gotten, but it seems like sense of depth is not there, and
the low frequencies are still not as good as the closest position.
Furthermore, I have to set it up and tear it down for every event, which is
not practical, and I have to block of audience seats so it's not the best
solution (and it's more obtrusive visually)

When another engineer was there from a major broadcaster, he used omnis
about 3 feet apart, and about a foot or so from the front edge of the stage
(the musicians are usually about 3 feet from the front edge of the stage on
average, but this varies depending on the group). He said omnis were the way
to go.

But now I'm reading that omnis need to be a spaced pair, and most people are
saying for orchestra, and talking 12 feet apart (which I've actually got the
receptacles in the ceiling for this, but we can't get to them easily!). And,
of course, I'd need any mounts to be coming down from the ceiling to be
unobtrusive. Additionally, I've read that omnis, if close together (like on
my current hanging setup), need a baffle, like a Jecklin or Schneider disc.
Both of these seem really reasonable in terms of how they mimic the spacing
of the human head (as does ORTF - but I'm reading that's only for
directional mics).

So what should I be doing? SHould I stick with my cardioids and try an ORTF
spacing instead of the XY coincident position they're in now (assuming I
can't change the position of the ceiling hanging setup). Or should I try and
use omnis in either a spaced pair or baffle system?

The way they are now is just not cutting it, and that's the reason I'm
leaning toward the omnis - I've been reading they offer a better alternative
for distant miking, better low frequency response, good stereo spread, and
better pickup of room ambience.

But I guess what I'm asking is, given the setup as I'm describing, what
would be the best way to put a permanent mic setup in this room????

TIA
Steve

For what it's worth, I have found ORTF to give a better sense of
spaciousness and ambiance than XY. If you play with the angle and
spacing a little, you might get exactly what you want. By increasing
the angle between the mics, you will pick up a bit more ambiance;
by increasing the space between the capsules, you will diffuse the
phase relationship between the mics a bit, giving a feeling of
spaciousness (I will no doubt get flamed for that statement, but done
properly, it can give a very pleasant effect without sacrificing the
clarity of the image).

A word of caution, however, too great a space and/or angle and you
will start to lose the fusion of the image in the center - a big
concern for small ensembles and soloists. This may be no small feat,
unless you have an assistant to stand on the ladder and tweak the
mic's while you listen in another room.

Or just get a 15 foot stand, and throw that in the 3rd row with an
ORTF pair. :-)

Steve Latham wrote:
THe problem is, I feel like the sound is a little cold and sterile. Part of
this is I'm not getting much ambient signal (and this is a great sounding
room, so I really feel it's an important part of the experience). The
ceiling is HIGH, and we can't even get to the receptacles without building
scaffolding (which has never happened in the 15 years this building has been
around). The mics hang in an XY pair about 15 feet above the front center
stage, maybe about a foot back from the very front edge of the stage. The
cable lengths, and fixed position in the receptacles prevents my moving them
too much, but I have been able to pull them back so now they hang about 2
feet past the edge of the stage (into the audience) and are now maybe a foot
higher (if that - it's just whatever the angle difference caused).

That's added a little ambience, but of course it's also lessened the low
frequency response a bit.

The low frequency difference might well be due to the change in height,
but maybe not. Pulling it back is what you need to do in order to get
more ambience. You could also try a microphone with a slightly wider
pattern if you're stuck up that close.

I've also pulled another pair of the same mics, tried an ORTF like
configuration (as best I could with the mount I have) and put them in the
third row, up on an Atlas stand - about 8 feet in the air - I was figuring
the greater horizontal distance from the sound source would make up for the
lower height than my hanging mics. This is the best stereo spread and warmth
(ambience) I've gotten, but it seems like sense of depth is not there, and
the low frequencies are still not as good as the closest position.
Furthermore, I have to set it up and tear it down for every event, which is
not practical, and I have to block of audience seats so it's not the best
solution (and it's more obtrusive visually)

In this case, the height of the microphone is so radically different that
it's hard to worry about any other differences. You probably want a
placement that is farther back than the original hung pair, but at a
similar height.

When another engineer was there from a major broadcaster, he used omnis
about 3 feet apart, and about a foot or so from the front edge of the stage
(the musicians are usually about 3 feet from the front edge of the stage on
average, but this varies depending on the group). He said omnis were the way
to go.

If you do A-B pair, you get weird imaging. Very odd sense of depth. Some
people like this, some people don't, but it's not natural. The close
spacing he is using will tend to collapse things and give you a little better
mono compatibility than a widely-spaced triad.

But now I'm reading that omnis need to be a spaced pair, and most people are
saying for orchestra, and talking 12 feet apart (which I've actually got the
receptacles in the ceiling for this, but we can't get to them easily!). And,
of course, I'd need any mounts to be coming down from the ceiling to be
unobtrusive. Additionally, I've read that omnis, if close together (like on
my current hanging setup), need a baffle, like a Jecklin or Schneider disc.
Both of these seem really reasonable in terms of how they mimic the spacing
of the human head (as does ORTF - but I'm reading that's only for
directional mics).

12 feet apart isn't unusual. Some folks (and the old Mercury recordings
are a fine example) use three omnis over the orchestra spaced very wide,
with the center one panned to center. I find this has very weird imaging
personally, but again some people like it. And I can live with it because
the tonality is good and that's more important to me than image.

Another possibility is to use a Jecklin disc or other baffled omni pair.
This allows you to get good ambience with very close placement.

So what should I be doing? SHould I stick with my cardioids and try an ORTF
spacing instead of the XY coincident position they're in now (assuming I
can't change the position of the ceiling hanging setup). Or should I try and
use omnis in either a spaced pair or baffle system?

The ORTF spacing is definitely a good idea, and it will give you more depth
but it won't give you any more actual ambience. If your problem is that
you are too close, you can try using wider cardioids up there.

You can also try omnis in several configurations if you have some around.
Also, you can try using a very tall stand and putting your existing cardioid
pair at the same height as it is when hung, but farther from the orchestra.
You can move it around a little bit and get a sense of how things change.

It helps to have an assistant who can move the stand around during a
rehearsal while you listen over speakers in the booth. Make sure you
have a real booth with speakers, even if it's actually a commandeered
dressing room or broom closet.

The way they are now is just not cutting it, and that's the reason I'm
leaning toward the omnis - I've been reading they offer a better alternative
for distant miking, better low frequency response, good stereo spread, and
better pickup of room ambience.

If you have omni capsules for the KM100s, you should definitely try them
just to get a sense of what they do. Record some rehearsals and get a sense
of how the different configurations work in that particular hall.

I don't recall the KM100s having wide-cardioid capsules available... I know
the Schoeps systems have a bunch of cardioid patterns, but I think with the
KM100 you are stuck with that one cardioid configuration.

But I guess what I'm asking is, given the setup as I'm describing, what
would be the best way to put a permanent mic setup in this room????

Play around with some temporary systems on tall stands. Find out what is
right FOR THAT ROOM and then build a permanent install to put the mikes
there.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Steve Latham wrote:

When another engineer was there from a major broadcaster, he used
omnis about 3 feet apart, and about a foot or so from the front
edge of the stage (the musicians are usually about 3 feet from the
front edge of the stage on average, but this varies depending on
the group). He said omnis were the way to go.

When using only a single pair of omnis the intercapsule distance range
to use is indeed between 1.5 and 3 feet, and 2 feet is a good starting
point. The sonic price is that it is very difficult to maintain a good
stereo imaging of the parts of the orchestra that are distant. It is
also generally relevant to avoid getting them to high above the
orchestra. Generally for all stereo pair recordings ambience amount is
adjusted by mic stand height and stereo spread by mic stand to sonic
object distance.

But now I'm reading that omnis need to be a spaced pair, and
most people are saying for orchestra, and talking 12 feet apart

For a pair, that is nonsense, it will create dual mono. With a center
mic it is a different tale.

So what should I be doing? SHould I stick with my cardioids and
try an ORTF spacing instead of the XY coincident position they're
in now

Probably yes. You may need to make two changes to the rigging: make it
be height adjustable and you may need a third wire so that you can
adjust the horisontal distance within say a 4 to 6 feet range.

The way they are now is just not cutting it, and that's the reason I'm
leaning toward the omnis

You can get excellent results with omni's. But it is a different way of
recording and you don't just put an omni pair where the cardioid pair
was and press record.

But I guess what I'm asking is, given the setup as I'm describing,
what would be the best way to put a permanent mic setup in this
room????

Supplement with an omnidirectional omni pair no further away than 6 feet
behind the cardioids, 2 feet spacing, aimed upwards, record 4 tracks.
4006's with nosecones constitute omnidirectional omni microphones from
10 Hz to about 16 kHz, with a slight upper midrange (relative) dip being
the sonic cost of true omnidirectionality. Use them with black grid if
the slight response unlinearity worries you, pointing the mics upwards
reduces the sonic cost of the on axis treble boost that black grid by
design causes.

YMMV - suggestions are only tentative, all kinds of real world concerns
will matter.

Steve


Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

"Steve Latham" wrote in message
...
Hello All, I'm a classical musician with some technical audio experience,
but not a real "engineer".

I'm recording in a beautiful sounding recital hall of about 200 seats. The
hall already had a pair of Neumann KM140s hanging from the ceiling. I'm
recording solo piano (Steinway grand), solo instruments, duets, trios,
quartets and so on. ABout the largest thing I get is a baroque string
ensemble (about 25-30 people) plus harpsichord.

THe problem is, I feel like the sound is a little cold and sterile. Part
of
this is I'm not getting much ambient signal (and this is a great sounding
room, so I really feel it's an important part of the experience). The
ceiling is HIGH, and we can't even get to the receptacles without building
scaffolding (which has never happened in the 15 years this building has
been
around). The mics hang in an XY pair about 15 feet above the front center
stage, maybe about a foot back from the very front edge of the stage. The
cable lengths, and fixed position in the receptacles prevents my moving
them
too much, but I have been able to pull them back so now they hang about 2
feet past the edge of the stage (into the audience) and are now maybe a
foot
higher (if that - it's just whatever the angle difference caused).

That's added a little ambience, but of course it's also lessened the low
frequency response a bit.

I've also pulled another pair of the same mics, tried an ORTF like
configuration (as best I could with the mount I have) and put them in the
third row, up on an Atlas stand - about 8 feet in the air - I was figuring
the greater horizontal distance from the sound source would make up for
the
lower height than my hanging mics. This is the best stereo spread and
warmth
(ambience) I've gotten, but it seems like sense of depth is not there, and
the low frequencies are still not as good as the closest position.
Furthermore, I have to set it up and tear it down for every event, which
is
not practical, and I have to block of audience seats so it's not the best
solution (and it's more obtrusive visually)

When another engineer was there from a major broadcaster, he used omnis
about 3 feet apart, and about a foot or so from the front edge of the
stage
(the musicians are usually about 3 feet from the front edge of the stage
on
average, but this varies depending on the group). He said omnis were the
way
to go.

But now I'm reading that omnis need to be a spaced pair, and most people
are
saying for orchestra, and talking 12 feet apart (which I've actually got
the
receptacles in the ceiling for this, but we can't get to them easily!).
And,
of course, I'd need any mounts to be coming down from the ceiling to be
unobtrusive. Additionally, I've read that omnis, if close together (like
on
my current hanging setup), need a baffle, like a Jecklin or Schneider
disc.
Both of these seem really reasonable in terms of how they mimic the
spacing
of the human head (as does ORTF - but I'm reading that's only for
directional mics).

So what should I be doing? SHould I stick with my cardioids and try an
ORTF
spacing instead of the XY coincident position they're in now (assuming I
can't change the position of the ceiling hanging setup). Or should I try
and
use omnis in either a spaced pair or baffle system?

The way they are now is just not cutting it, and that's the reason I'm
leaning toward the omnis - I've been reading they offer a better
alternative
for distant miking, better low frequency response, good stereo spread, and
better pickup of room ambience.

But I guess what I'm asking is, given the setup as I'm describing, what
would be the best way to put a permanent mic setup in this room????


You've gotten some very good advice from Scott and locosoundman. It squares
with the things I would have recommended. I'd definitely play with the
omni's...if the acoustics are good (and you say they are) then three spaced
omni's six-eight feet apart might do it. They pick up even ambiance and are
not rolled off in the bass like either cardioids or figure-eights.

There is no substitute for experimentation. Every room has its sweet spots,
and every configuration its strengths and weaknesses. Finding the right
combination can take days...but once its found, you can keep it forever.

Thanks everyone!

Just to refine a bit:

You're suggesting that 12 feet apart without a third center mic for omnis is
no good, which is what my gut instinct was telling me.

It seems like my research is telling me that if you use an A-B pair (and I'm
trying to also keep things simple so blending a third mic in is not
practical) and space them 2 feet (give or take) apart, you can toy with the
placement and get what I'm after.

But, when they're close, there needs to be a baffle between them. How close
is close? Schneider setups and ORTF both use the average human head
dimensions for spacing the capsules, so, Dumb question: can you put omnis on
and ORTF mount (well, I know you can, but is it usable)? If you can, do you
need a baffle? If you can't what's the minimum distance apart they should be
without a baffle (I got between 20 and 80 cm from Neumann, but we hadn't
discussed if that was with or without baffle).

Thanks again, and looking forward to your responses,

Steve

BTW nsemble is what we call them in the South, pronounced, "eyn - sem -
blee" :-)

You're suggesting that 12 feet apart without a third center mic for omnis is
no good, which is what my gut instinct was telling me.

Yeah. Widely spaced omnis give an exaggerrated stereo spread with no real
center imaging. It's a very confused sounding sense of stereo.


Scott Fraser

Also, be aware that there is no one-size-fits-all approach & you WILL need to
change your setup to accomodate different instrument combinations in that
space.

Scott Fraser

ScotFraser wrote:
You're suggesting that 12 feet apart without a third center mic for omnis is
no good, which is what my gut instinct was telling me.

Yeah. Widely spaced omnis give an exaggerrated stereo spread with no real
center imaging. It's a very confused sounding sense of stereo.

BUT the tonality is good, and even though the stereo image is pretty weird,
it can work in some halls with acoustical problems in the rear.

Get the Mercury Living Presence CD of the Osipov State Balalaika Orchestra
to get a sense of how this sounds. It's a hell of a good band, too. If
that's too weird, try the recording of Petrouchka. All of these were done
with a spaced triad of large omni mikes suspended above the group (and
sometimes forward).
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

BUT the tonality is good, and even though the stereo image is pretty weird,
it can work in some halls with acoustical problems in the rear.

Which makes it a good starting place for a hybrid approach; spaced omni pair
with XY or ORTF center pair, or even center omni added.

All of these were done
with a spaced triad of large omni mikes suspended above the group (and
sometimes forward).

Well, three omnis is whole other ball game than a spaced pair. To me it's sort
like one third the way toward spot miking everything.





Scott Fraser

ScotFraser wrote:
BUT the tonality is good, and even though the stereo image is pretty weird,
it can work in some halls with acoustical problems in the rear.

Which makes it a good starting place for a hybrid approach; spaced omni pair
with XY or ORTF center pair, or even center omni added.

See, I never liked this... I always feel like something unpleasant is going
on when I bring the spaced pair up.

But if you can keep the orchestra out of the spaced pair, you might have
something.

All of these were done
with a spaced triad of large omni mikes suspended above the group (and
sometimes forward).

Well, three omnis is whole other ball game than a spaced pair. To me it's sort
like one third the way toward spot miking everything.

You get wide amplitude differences between channels, and the phase differences
are so great (and so unpredictable) that they don't really contribute all
that much to real imaging effects, I think. Lots of people like it, as
witnessed by the insane valuation on old Mercury and Everest LPs.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Steve Latham wrote:

Thanks everyone!

Just to refine a bit:

You're suggesting that 12 feet apart without a third center mic for omnis is
no good, which is what my gut instinct was telling me.

It seems like my research is telling me that if you use an A-B pair (and I'm
trying to also keep things simple so blending a third mic in is not
practical) and space them 2 feet (give or take) apart, you can toy with the
placement and get what I'm after.

Yes.

But, when they're close, there needs to be a baffle between them. How close
is close?

1 foot or less. You have to see this in the context of the depth of
stage, the deeper the stage, the wider they need to be apart to get good
stereo separation for the rearmost sources. You will have to balance
that need with the need for modest separation to get proper center
definition for the front most sources and to avoid them jumping
left-to-right or vice versa with no "inbetween". This can be a major
concern with things like flute, violin and viola and indeed with say
clarinet or oboe when playing solo up front.

Do be aware that these concerns apply for all stereo mic setups, except
perhaps for one-point X-Y which has strict "angular imaging". Speaking
of one-point, then a one-point MS-stereo setup might prove very useful,
I'll leave additional ascii on those setups to those that use them.

Schneider setups and ORTF both use the average human head dimensions
for spacing the capsules,

Yes, but what it really is about is the amount of decorrelation to
obtain between the channels. If you want to dive deep into this there is
the "Stereophonic Zoom" AES paper from 1983 and the recent DPA report of
their 5+1 experiments in Bannf.

Steve

As usual: ymmmv ....


Kind regards

Peter Larsen


--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Scott Dorsey wrote:

ScotFraser wrote:

You're suggesting that 12 feet apart without a third center mic for omnis is
no good, which is what my gut instinct was telling me.

Yeah. Widely spaced omnis give an exaggerrated stereo spread with no real
center imaging. It's a very confused sounding sense of stereo.


BUT the tonality is good, and even though the stereo image is pretty weird,
it can work in some halls with acoustical problems in the rear.

Get the Mercury Living Presence CD of the Osipov State Balalaika Orchestra
to get a sense of how this sounds. It's a hell of a good band, too. If
that's too weird, try the recording of Petrouchka. All of these were done
with a spaced triad of large omni mikes suspended above the group (and
sometimes forward).

I keep hearing about 3.0 SACDs made from the original 3-track masters. Rumor has it that playing them back on an LCR array sounds far better than the stereo mix...

In reply to message
posted by "Steve Latham" :

I think there are likely two problems with your permanent rig: its
position so close to the stage front, and the use of an XY
configuration. The fact that you get a nice sound in row 3 is
consistant with my experience recording chamber music in halls of
similar size. Now that you know where the sweet spot is for
direct/reverberant balance, you shouldn't try to fight it. Put the
mics there and then figure out how to get the image width (and depth)
and the tonal balance that you desire.

A coincident pair will not produce a satisfactory spread from this
position, so ORTF was a good place to start. But you can control the
image width by varying both the spacing and the angle between the
mics. Moreover, by trading one against the other, you can control the
central "focus" of the sound stage. The Michael Williams "Stereophonic
Zoom" monograph is essential reading in understanding how to do this.

Once you've optimized the above, you should experiment with changing
the array height. See the white paper on Bob Katz's Digital Domain web
site for a diagram of how this affects the sense of depth in a
recording. But be aware that changing the array height can also change
the tonality dramatically, either for better or for worse. It's going
to be a compromise, and the best advice is to have an assistant move
the stand up and down while you listen in the control room.

Unfortunately, the optimal choices will vary from ensemble to
ensemble. So when you design your "permanent" rig, pay particular
attention to making it easy change. You want an adjustable stereo bar
(the AEA one is lovely, but pricey), and you want to be able to raise
and lower the array easily, both for sonic reasons, and to readjust
the stereo bar. Ron Streicher has a lot of great rigging ideas which
he's taught in AES convention talks and at Aspen. (I love the modified
bait-casting reels!) I'm not certain if these are shown anywhere in
print, but it might be worth a phone call or email, once you have a
basic idea of what you need to accomplish.

Best of luck,

David L. Rick
Seventh String Recording
("reply to" goes nowhere; use davidDOTrickAThachDOTcom)

See, I never liked this... I always feel like something unpleasant is going
on when I bring the spaced pair up.

Overly wide image, or too much random phase?


Scott Fraser

ScotFraser wrote:
See, I never liked this... I always feel like something unpleasant is going
on when I bring the spaced pair up.

Overly wide image, or too much random phase?

It's not just that things get wider, the tone of the room changes and
I guess things start to smear (not in position, but in tone). Probably
that's a random phase issue.

This doesn't seem to bother many other folks. The fellow doing the NPR
broadcasts down in Norfolk is very gung-ho about this method and is very
happy with it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(David L. Rick) wrote in message . com...
In reply to message
posted by "Steve Latham" :

Yeah - one problem with a permanent, un-adjustable install is that it
will always be a compromise. The sweet spot in the room and the
optimal mic configuration will change with the ensemble,
unfortunately. If you have good cardioids like the Schoeps MK4's or
the Neumann KM80-whatever, ORTF or a variant thereof will probably be
the safest, most predictable thing.

Spaced omnis are nice for orchestras and pipe organs - but 12 feet -
yikes! - 2-5 feet is plenty. Anything around 10- 12 feet and you will
need a center mic or even an XY-pair in the middle. I am always leary
of that sort of thing though because phase can be a big problem.